The invention relates to an apparatus to precisely locate an arrow embedded in a target, such as a dart in a game of darts.
Dart games are popular in England and are gaining in popularity in the United States. Traditionally, after an arrow or dart has been thrown into the target, a person has to visually inspect the target to determine where the arrow landed. That person has to then calculate the score according to the rules of the game being played. The applications for such devices include use in places of entertainment and in dart leagues and dart tournaments.
The prior art includes complex apparatus used for diversified purposes:
The apparatus shown in U.S. Pat. No. 4,845,346 Touch Panel Having Parallax Compensation and Intermediate Coordinate Determination uses light sources and light receiving elements in sequentially driven pairs to accomplish a scan operation, and uses an interrupted signal to determine position.
U.S. Pat. No. 4,187,545 Article Orientation Determining Apparatus employs a column of sequentially pulsed radiation emitters and corresponding detectors and develops binary data indicative of the number of emitters that are unblocked during each scan.
U.S. Pat. No. 4,243,877 Electro-Optical Target For An Electro-Optical Alignment Measuring System describes a reflective target that includes a photoelectric sensor for producing an electric signal indicative of the lateral displacement of the reflective target and a reflective surface (mirror) for returning a portion of the optical reference beam to a photo sensor positioned adjacent the reference beam source to provide information relative to the angular position of the reflective target.
U.S. Pat. No. 4,346,994 Secondary Alignment Target For An Electro-Optical Alignment Measuring System employs a beam splitter in which the refracted sub-portion furnishes optical information regarding transverse orientation of the target, while the reflected sub-portion is re-reflected by the beam splitter to furnish a return beam containing optical information regarding rotational orientation of the target.
The apparatus shown in U.S. Pat. No. 4,052,066 Light-Emission Gun Amusement Machine For Home Use comprises of a light source, screen, and mirror as disposed between the screen and light source.
The apparatus shown in U.S. Pat. No. 4,281,926 Method and Means For Analyzing Sphero-Cylindrical Optical Systems utilizes a beam splitter and mirror for finding the refractive properties of lenses.
The apparatus shown in U.S. Pat. No. 5,154,404 Jam Detector For Inserter utilizes horizontal and vertical photo sensors and associated retro-reflective targets to detect jams by sensing an interruption of the horizontal beam and an uninterrupted retro-reflection of the vertical beam.
U.S. Pat. No. 5,154,002 Probe, Motion Guiding Device, Position Sensing Apparatus, and Position Sensing Method has a differential optical transducer which has two light source elements which emit light beams and two light sensor elements which receive these beams and a electronic circuit that compares the signal from light sensor elements and provides an output signal which indicates the position of the second member relative to the first member.
The apparatus shown in U.S. Pat. No. 3,877,816 Remote-Angle-of-Rotation Measurement Device Using Light Modulation and Electro-Optical Sensors includes a rotating disc-type linear polarizer in combination with a reference linear polarizer and a target linear polarizer. The photo sensors are arranged to receive modulated light separately from the target and reference polarizer and sinusoidal output signals representative of the modulated light received by the photo sensors are generated.
While such apparatus are suitable for some applications, they are not wholly satisfactory. The noted patented inventions apply to a myriad of diverse inventions, having only a casual relationship to the present apparatus.
It is an object of the invention to provide apparatus to precisely locate an arrow in a target.
It is an object of the invention to display the score of a dart game.
Another object of the invention is to provide apparatus that will function with a standard, unmodified bristle board target and standard unmodified darts.
Still another object of the invention is to be able to program different game rules into the apparatus and to calculate the score.
It is yet another object of the present invention to provide apparatus that is reliable.
It is an object of the invention to provide apparatus which is inexpensive to manufacture.
It is also an object of the invention to enable the apparatus to be used with targets of various diameters.